Subgraphs broken in latest release

[Chris]

I am not sure of the intended usage of subgraphs with pydot. But
there appears to be a bug with subgraphs. If a subgraph is added to a
graph the obj_dict is saved, only. I believe this was done for
performance reasons as stated on your blog.

But when a user tries to retrieve a subgraph via a name, the
"get_subgraph" function will return a list of subgraphs. One Subgraph
for each obj_dict entry. In my example I created only one subgraph
and was returned 12 subgraphs. Below is a little example that
illustrates the issue.

This only worked when I modified get_subgraph to use the name argument
and not the non-existing sgraph variable.

There seems to be a 1 bug (use of sgraph in get_subgraph) and a
design / architecture issue in get_subgraph.

$ python
Python 2.5.4 (r254:67916, Dec 23 2008, 15:10:54) [MSC v.1310 32 bit
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import pydot
>>> graph = pydot.Dot("graph")
>>> graph.add_node(pydot.Node("node1"))
>>> graph.add_node(pydot.Node("node2"))
>>> graph.add_subgraph(pydot.Subgraph("subgraph1"))
>>> graph.get_subgraph("subgraph1")
[<pydot.Subgraph object at 0x00DE20D0>, <pydot.Subgraph object at
0x00DE2110>, <pydot.Su
t at 0x00DFE5D0>, <pydot.Subgraph object at 0x00E02E10>,
<pydot.Subgraph object at 0x00E
>>> len(graph.get_subgraph("subgraph1"))
12
>>>

I don't believe the above example is the intended results. I believe
the intended usage would be for 1 Subgraph to be returned constructed
on the 12 dictionary values (obj_dict) saved. But instead a Subgraph
is created for each dict entry. This seems to be a common error with
all Subgraph functions.

Thanks
Chris